1331686440 has 512 divisors, whose sum is σ = 5455872000. Its totient is φ = 282175488.

The previous prime is 1331686423. The next prime is 1331686451. The reversal of 1331686440 is 446861331.

It is a happy number.

1331686440 is a `hidden beast` number, since 1 + 3 + 3 + 1 + 6 + 8 + 644 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1331686395 and 1331686404.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 10485657 + ... + 10485783.

It is an arithmetic number, because the mean of its divisors is an integer number (10656000).

Almost surely, 2^1331686440 is an apocalyptic number.

1331686440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1331686440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2727936000).

1331686440 is an abundant number, since it is smaller than the sum of its proper divisors (4124185560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1331686440 is a wasteful number, since it uses less digits than its factorization.

1331686440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246 (or 236 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 1331686440 is about 36492.2791834108. The cubic root of 1331686440 is about 1100.1890694290.

The spelling of 1331686440 in words is "one billion, three hundred thirty-one million, six hundred eighty-six thousand, four hundred forty".